ozone therapy in prevention and treatment of in …ozone in prevention and treatment of fissure and...
TRANSCRIPT
Riga, 2017
Speciality – Dentistry
Summary of Doctoral Thesisfor obtaining the degree of Doctor of Medicine
OZONE THERAPY IN PREVENTION AND TREATMENT OF IN CARIES
IN PERMANENT TEETH
Jūlija Kalniņa
The study was carried out at Rīga Stradiņš University Department of Dental Therapy and Oral Health.
Scientific supervisor: Dr. med., Professor Rūta Care, Rīga Stradiņš University, Latvia
Official reviewers: Dr. med., Professor Ilga Urtāne, Rīga Stradiņš University, LatviaDr. habil. med., Professor Pēteris Apse, SIA Adenta, LatviaDr. med. Daiga Kviļūna, University Children’s Hospital, Latvia
Defence of the Doctoral Thesis will take place at the public session of the Doctoral Council of Medicine on 1 March 2017 at 14.30 in Hippocrates Lecture Theatre, Dzirciema Street 16, Rīga Stradiņš University.
Doctoral Thesis is available at the library of Rīga Stradiņš University and on the website www.rsu.lv.
Secretary of the Promotional Council:Dr. med. Professor Anda Brinkmane
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CONTENT
CONTENT.......................................................................................................... 3 SUMMARY........................................................................................................ 5 ABBREVIATIONS USED IN THE STUDY ..................................................... 7 INTRODUCTION .............................................................................................. 8
The Aim of the Study .................................................................................. 10 Tasks of the Study ....................................................................................... 10 Hypothesis of the Study .............................................................................. 10 Scientific novelty of the Study .................................................................... 11
1. MATERIAL AND METHODS ............................................................. 12 1.1. The design of the study .................................................................. 12 1.2. Assessment of oral health .............................................................. 15
1.2.1. Assessment of dental status ..................................................... 15 1.2.2. Assessment of plaque and dental calculus ............................... 16 1.2.3. Assessment of periodontal status ............................................. 17
1.3. Clinical examination ...................................................................... 18 1.4. Preventive treatment of premolars with ozone, fluoride varnish, and a sealant................................................................................... 19 1.5. Treatment of occlusal caries of permanent molars with ozone and fluoride varnish ....................................................................... 20 1.6. Questionnaire on oral care and children's dietary habits ................ 21 1.7. Processing of statistical data of the research .................................. 21 1.8. Ethical considerations of the study ................................................ 22
2. RESULTS ..................................................................................................... 23 2.1. Analysis of oral health status in the study group .................................. 23
2.1.1. Caries intensity ........................................................................ 23 2.1.2. Oral hygiene ............................................................................ 26 2.1.3. Periodontal status .................................................................... 26 2.1.4. Analysis of children dietary and oral care habits ..................... 27
2.2. The effectiveness of Ozone on tooth tissue mineralization in caries prevention in premolars ....................................................... 30
2.2.1. Impact on development of caries ............................................. 30 2.2.2. Changes of oral health during the study .................................. 31
2.3. The effectiveness of Ozone on tooth tissue mineralization in caries treatment in permanent molars ............................................ 34
2.3.1. Impact on the development of caries and DIAGNOdent readings ............................................................................................... 34 2.3.2. Oral health changes during the study ........................................ 36
3. DISCUSION ................................................................................................. 39 3.1. Analysis of oral health status in the study group ................................ 39 3.2. The effectiveness of Ozone on tooth tissue mineralization in
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caries prevention in premolars ........................................................... 43 3.3. The effectiveness of Ozone on tooth tissue mineralization in caries treatment in permanent molars ................................................. 47
4. CONCLUSIONS .......................................................................................... 51 5. PRACTICAL RECOMMENDATIONS ...................................................... 52 6. SCIENTIFIC PUBLICATIONS AND REPORTS ON THE STUDY ......... 53 7. BIBLIOGRAPHY ........................................................................................ 55
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SUMMARY Caries is one of the most common oral diseases. Ozone therapy is one of
the latest techniques in dentistry which is applied for caries prevention and
treatment. Ozone destroys cariogenic bacteria, thus eliminating one of the main
caries aetiological factors. It is believed that ozone therapy can prevent or stop
progression of caries, which usually leads to drilling and filling of teeth. Caries
prevention and treatment using ozone is a new method in Latvia.
Several studies have demonstrated beneficial effects of ozone on
treatment of root caries both in vitro and in vivo. However, data on the role of
ozone in prevention and treatment of fissure and pit caries, which is one of the
most frequently occurring types of caries in children and adolescents, is still
very controversial. Given the fact that caries incidence in Latvia is high, it is
important to pay close attention to prevention of early enamel caries.
The aim of the study was to determine the efficiency of ozone in caries
prevention in premolars and treatment of initial enamel caries treatment in
permanent molars in children by assessment of changes in mineralization of
dental tissues.
The main objective of the study was to assess changes in dental tissues
after ozone therapy in the period of 24 months.
The study included ten-year-old children. At this age, it is important to
protect teeth from occlusal surface caries, because it is difficult to provide good
cleaning of dental surfaces and self-cleaning by means of chewing. During the
study, the incidence of caries, oral hygiene and periodontal status of children
was determined and assessed, and analysis of dietary behaviour was performed.
Active dental change takes place during early adolescence which we were able
to follow up during the study. In addition, there are very few studies
worldwide, which include children of this age group.
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Many different caries prevention methods are available world-wide, our
task was to assess the efficiency of application of ozone, fluoride varnish and
sealants on development of caries in newly erupded premolars. This study is
unique for it is the first time in Latvia when ozone therapy was studied in
pediatric dentistry.
By using laser infused fluorescence device DIAGNOdent which is not
very popular in Latvia, but is well-known abroad, efficacy of ozone and
fluoride varnish in therapy of initial occlusal enamel caries in permanent molars
was determined. Our study is the only study in Latvia, in which this early caries
diagnostic and monitoring instrument was applied.
Caries in premolars developed equally often in ozone, in fluoride
varnish, and in sealants groups. Therefore, it is not important what preventive
measures we use. We concluded that ozone is an effective way of treatment of
initial enamel caries in permanent molars. This indicates the need for the
earliest possible commencement of preventive treatment of initial enamel
caries.
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ABBREVIATIONS USED IN THE STUDY
AAPD − American Academy of Paediatrics Dentistry B − buccal BW – BiteWing X-ray images CO2 − carbon dioxide CPITN − Community Periodontal Index of Treatment Needs d − dent DB − disto-buccal DL − disto-lingual y. − year y.o.a. − years of age Ci − initial enamel caries DMF S − Caries intensity index for dental surfaces in permanent
occlusion DMF T − Caries intensity index for dental in permanent occlusion L − lingual MB − mesio-buccal ML − mesiolingual n − numero (number)
p − filled primary teeth p – statistical significance (the probability of obtaining at least
as extreme results given that the null hypothesis is true) pH − a numeric scale used to specify hydrogen ion concentration
in solution ppm − part per million (equals to mmol/l) X-ray – radiological imaging SD − standard deviation V − vestibular WHO − World Health Organization
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INTRODUCTION Caries is the main oral health problem affecting 60–90% of school-age
children (Petersen, 2003; Rickard et al., 2004; Almaz and Sonmez, 2013).
Thanks to modern prevention methods, which allow treatment and stopping of
caries at an early stage of its development, it is possible to achieve significant
reduction in intensity of caries (Marthaler, 2004; Neuhaus et al., 2009). It is
important to identify as early as possible the initial enamel lesions to prevent
their progression, and it is considered to be more effective means than filling
(Johansson et al., 2014).
In recent years, we have been faced with highly neglected dental decays
in increasingly younger children. Latvian children under 18 years of age have
high caries prevalence and intensity. In Riga in 2001, (carious, filled and
extracted teeth) index in 11-year-old adolescents was 1.75, while in the group
of 15-years-old children it was – 7.04 (Bērziņa and Care, 2003). Data of the
Department of Children Dentistry of Rīga Stradiņš University show sharp
growth of caries incidence in early age, as in 2010, 926 children underwent
dental treatment under general anaesthesia in the Department of Children
Dentistry, while in 2001 – 85 children. From 2000 to 2014, 15 594 children
were treated under general anaesthesia (Ciganoviča and Care, 2012). This fact
once again underlines the importance of timely protection of teeth from caries,
to reduce the number of children in need of dental treatment.
It is known, that micro-organisms play an important role in causing and
development of caries (Polydorou et al., 2012). One of caries prevention
strategies is reduction of the number of caries-causing micro-organisms in
plaque, thereby preventing formation and development of caries (Johansson
et al., 2009). For this purpose, various antimicrobials are used, which can
mechanically and / or chemically reduce development of dental biofilm and
amount of bacteria (Polydorou et al., 2012).
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Ozone therapy is one of the new methods in dentistry, making it possible
to treat dental decay without drilling (Castillo et al., 2008). Ozone is widely
used due to its antibacterial, disinfectant and healing properties (Nogales et al.,
2008). Ozone destroys cariogenic bacteria, thus eliminating one of the main
caries aetiological factors (Azarpazhooh and Limeback, 2008). Interest in
“biological” approach in treatment of caries rapidly increases, considering
caries as an infectious disease (Tyas et al., 2000).
First permanent molars are subjected to the greatest risk of caries
because they erupt as early as at six to seven years of age and often are
insufficiently cleaned. Occlusal fissure and pit caries constitutes majority of
carious lesions in children aged from 8 to 15 years (Baysan and Lunch, 2006).
To protect premolar and molar fissures, traditionally sealants and fluoride
containing preparations are used. In recent years, prevention and treatment of
caries using ozone, increasingly becomes more and more popular, while in
Latvia it is still a novelty. It is a non-invasive, painless and quick method. This
is a very important factor because many children are still afraid of dentists.
Ozone has highly strong antimicrobial properties; it disrupts bacterial cell
membranes, in the result of which bacteria die (Nogales et al., 2008).
Laboratory studies have shown that ozone significantly reduces the number of
micro-organisms in carious dentin in a very short period of time, thus
improving dental remineralisation (Nagayoshi et al., 2004). Taking into account
the properties of ozone, it would be clinically important to check properties and
effectiveness of ozone in carious prevention and dental treatment in children as
introduction of new technologies enhances quality of prevention and treatment,
shortens time required for treatment and is a benefit not only for a patient but
also for a dentist.
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The Aim of the Study
To determine efficiency of the use of ozone through assessment of
changes in mineralization of dental tissues, in prevention of initial enamel
caries of children, and in treatment of permanent teeth.
Tasks of the Study
1. To analyze the oral health status in the study group.
2. To evaluate the changes in dental tissues after ozone, fluoride varnish and
sealants use after 6, 12, 18 and 24 months, and to determine the effects of
ozone to mineralization process in caries prevention in premolars.
3. To evaluate the changes in dental tissues after ozone and fluoride varnishes
use after 6, 12, 18 and 24 months, and to determine the effects of ozone to
mineralization process at an early enamel caries treatment in molars.
Hypothesis of the Study
1. Ozone is an effective agent in prevention of early enamel caries in
premolars.
2. Ozone is an effective agent in treatment of early enamel caries in molars.
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Scientific novelty of the Study
For the first time in Latvia, there was conducted a study with application
of a new method in treatment and prevention of early enamel caries – ozone
therapy. In the scientific paper, caries development was assessed with laser
infused fluorescence device DIAGNOdent which is a new method in Latvia.
Within two years we assessed changes in dental tissues after the use of ozone
and various popular prophylactics (fluoride varnish and sealants). The study
results showed potentialities of ozone in prevention and treatment of caries in
permanent premolars and molars.
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1. MATERIAL AND METHODS
1.1. The design of the study Cohort, longitudinal study “Application of ozone in prevention and
treatment of caries in permanent teeth” was conducted at the Institute of
Dentistry of Riga Stradins University in the period from September 2012 to
October 2014. The study included ten-year-old children. This age of children
was selected based on stage of development of molars and premolars – teeth
necessary for the study.
Patients who were selected from the database of the Institute of
Dentistry of RSU (n = 1648), were born from 1 January 2002 until 31
December 2002. Of them, 400 children (200 girls and 200 boys) were randomly
included in the study, and letters of invitation to participate in the study were
dispatched to their parents. Only 158 children (70 girls and 88 boys) attended
the first appointment. The study was approved by the Ethics Committee of Rīga
Stradiņš University.
The study included three parts: (See Figure 1.1.)
Figure 1.1. Schematic representation of the study
158 children participated (70 girls and 88 boys) in the first part of the
study who responded to an invitation to participate in the study and to attend
Part One •Analysis of oral health status in the study group
Part Two
•The effectiveness of Ozone on tooth tissue mineralization in caries prevention in premolars.
Part Three
•The effectiveness of Ozone on tooth tissue mineralization in caries treatment in molars.
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the first appointment. 158 parents with their children during this visit filled out
a questionnaire about the children’s oral care and dietary habits. Repeated
examinations were performed every 6 months within the period of 2 years. The
study concluded with 120 children remained therein. The total of compliance of
patients was – 75.9%. Delays of appointment schedules were the most common
reasons for withdrawal from the study.
Of all 158 children who arrived for the first appointment, 122 children
were selected for the second part of the study. Inclusion criteria: at least
2 intact, erupted premolars. Exclusion criteria: history of bronchial asthma.
Children were divided into 4 groups: 3 therapy groups (applying
different means of prevention) – fluoride varnishes, sealants, ozone and
1 control group. The groups of fluoride varnishes and sealants were used as an
active control group. For distribution of patients in groups see Figure 1.2.
Figure 1.2. Distribution of patients of the second part of the study
540 premolars 122 patients
At baseline
6 months
12 months
18 months
24 months
Ozone group 110 premolars
20 patients
103 premolars 19 patients
100 premolars 19 patients
100 premolars 19 patients
92 premolars 17 patients
Varnish group 110 premolars
22 patients
103 premolars 21 patients
103 premolars 21 patients
103 premolars 21 patients
88 premolars 19 patients
Sealants group 110 premolars
22 patients
78 premolars 18 patients
78 premolars 18 patients
78 premolars 18 patients
75 premolars 16 patients
Control group 210 premolāri
58 patients
173 premolars 50 patients
169 premolars 50 patients
156 premolars 47 patients
130 premolars 43 patients
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During the study, for various reasons, participation in the study was
suspended by 15% of children in the ozone group, 13.7% – in the varnish
group, and 27.3% – in the sealants group, while in the control group – 25.9% of
children. In total, 27 children not arrived for a dental appointment. Delays in
appointment schedules were the most common reasons for withdrawal from
participation in the study.
Of all 158 children who arrived for the first appointment, 49 children
were selected for the third part of the study. Inclusion criteria: at least 2 fully
erupted molars with early enamel caries diagnosed by laser infused
fluorescence device (DIAGNOdent, KaVo) in occlusal surfaces – DIAGNOdent
value – 11 to 20. Exclusion criteria: history of bronchial asthma, glucose-6-
phosphate dehydrogenase deficiency, hyperthyroidism, severe anaemia,
thrombocytopenia.
Children were divided into 3 groups: the ozone group (new method of
therapy), the varnish group (conventional method of treatment, as an active
control group), and the control group (see Figure 1.3.). In total, 88 teeth were
studied. Patients’ compliance in this part of the study was 93.3% in the control
group and 94% in the varnish and ozone groups. 6% (n=3) of children
suspended their participation in the study. Delays of appointment schedules
were the most common reasons for withdrawal from the study.
15
Figure 1.3. Distribution of patients of the part three of the study
1.2. Assessment of oral health DMF, CPITN and Greene-Vermillion index was determined in the
children of the study. Data were recorded in patient records (WHO Oral Health
Assessment Form, 1987). X-ray examination (BW×2) was carried out for the
teeth.
1.2.1. Assessment of dental status Caries intensity was determined for teeth and surfaces by DMF index.
This characterizes the intensity of caries in an individual or a group of people.
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The DMF expresses the amount of carious, filled and extracted teeth or
surfaces.
Dental status was investigated using radiographic examination (BW×2).
Twice a year measurements were made using laser infused fluorescence device
DIAGNOdent on occlusal surfaces of molars in order to determine changes of
mineralization in dental tissues. Measurements were recorded in a table.
Initial enamel caries was defined as primary or clearly visible changes in
dental enamel. In registration of data the following codes were used:
Table 1.1.
Codes for recording of initial enamel caries
Scores Criteria
0
No shadow or stained area
1
Lesion stays the same width when transilluminated / Thin grey shadow into enamel when transilluminated
2
Wide grey shadow into enamel when transilluminated
1.2.2. Assessment of plaque and dental calculus For assessment plaque and dental calculus, a simplified Greene -
Vermillion oral hygiene index (Greene and Vermillion, 1964) was used, which
is determined for six teeth (dd 16, 11, 26, 31 buccal and 46, 36 lingual). It is
marked by codes – for plaque and for dental calculus (see Table 1.2.).
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Table 1.2.
Applicable codes for assessment of plaque and dental calculus
Criteria for classifying debris Scores Criteria 0 No debris or stain present
1 Soft debris covering not more than one third of the tooth surface, or presence of extrinsic stains without other debris regardless of surface area covered
2 Soft debris covering more than one third, but not more than two thirds, of the exposed tooth surface.
3 Soft debris covering more than two thirds of the exposed tooth surface. Criteria for classifying calculus
Scores Criteria 0 No calculus present
1 Supragingival calculus covering not more than third of the exposed tooth surface.
2
Supragingival calculus covering more than one third but not more than two thirds of the exposed tooth surface or the presence of individual flecks of subgingival calculus around the cervical portion of the tooth or both.
3 Supragingival calculus covering more than two third of the exposed tooth surface or a continuos heavy band of subgingival calculus around the cervical portion of the tooth or both.
1.2.3. Assessment of periodontal status Periodontal status was assessed by CPITN (Community Periodontal
Index of Treatment Needs) index, which determines periodontal status and
treatment needs. For children up to the age of 19 – only six teeth are being
examined: d17/16; d11; d26/27; d36/37; d31; d46/47. The following codes
were used for registration of periodontal status (see Table 1.3.).
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Table 1.3.
Periodontal status recording criteria
Scores Criteria 2 calculus felt during probing but all the black area of the visible 1 bleeding observed, directly or by using mouth mirror, after sensing 0 healthy 9 Tooth is not possible to investigate (difficult access or patient
cooperates) X If there are not at least two teeth remaining and not indicated for
extraction in a sextant, the appropriate box should be cancelled
1.3. Clinical examination Clinical examination was carried out in a dental chair, using standard
lighting and dental instruments: mirror, blunt probe and graduated button
probe. Examination of patients was conducted by the author of the study.
All children of the study, every 6 months for 2 years underwent
determination of caries intensity both in permanent and milk teeth and surfaces
by DMF index.
X-ray examination (BW×2) was carried out once a year. Plaque and
dental tartar, as well as CPITN index in children was determined every six
months for two years.
Twice a year measurements were made using laser infused fluorescence
device DIAGNOdent on occlusal surfaces of molars in order to determine
changes of mineralization in dental tissues. Before each measurement,
calibration was carried out for each tooth individually. The highest value was
recorded in each tooth.
The initial caries was determined every 6 months for two years.
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1.4. Preventive treatment of premolars with ozone, fluoride varnish, and a sealant
In the beginning of the study and every 6 months for 2 years,
122 children of three premolar caries prevention groups of the study (ozone,
fluoride varnish, sealants groups), as well as children of the control group
underwent polish of teeth with fluoride-free polishing paste and:
• children in the ozone group underwent 6-second ozone application on
intact premolars. After ozonation, teeth were covered with a fluoride
solution. After the application, patients were not allowed to eat foods
and rinse mouth for 4 hours. They were instructed in oral hygiene,
which included mandatory brushing twice a day with fluoride
containing toothpaste (at least 1000 ppm).
• In the fluoride varnish group, fluoride containing varnish (Fluocal
solute, Septodont, France) was applied on intact premolars of
children. After the application, patients were advised to avoid rinsing
their mouths, eating solid foods for 4 hours and cleaning their teeth
until the next day morning. Patients were instructed in oral hygiene,
which included mandatory brushing twice a day with a fluoride
containing toothpaste;
• in the group of sealants, intact premolar fissures were treated with
37% orthophosphoric acid, which was rinsed away after 15 seconds of
etching. Tooth drying was followed by application of a sealant
(Clinpro 3M ESPE Dental Products, St. Paul, USA). The highest
points were tested with articulation wrapper which in case of need
were removed by a micro-motor and a polishing-drill. Patients were
instructed in oral hygiene, which included mandatory brushing twice a
day with a fluoride containing toothpaste;
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• in the control group the intact premolars remained untreated.
Every 6 months’ patients had dental appointments in order to determine
efficiency of chosen prevention methods (development of caries in treated
surfaces). If caries had not developed, an application of fluoride varnish and re-
application of ozone was carried out. If necessary, if any of the sealants was
expelled or partially expelled, it was applied repeatedly.
1.5. Treatment of occlusal caries of permanent molars with ozone and fluoride varnish
At baseline of the study and after every 6 months for 2 years, for
treatment of caries in permanent molars in both therapy groups (ozone and
fluoride varnishes), as well as in the control group, teeth were polished with
fluoride-free polishing paste and:
• In the ozone group, after polishing, a molar was dried and a
measurement with laser infused fluorescence device (DIAGNOdent,
KaVo, Germany) was made for registration of depth of dental caries
(demineralization) in occlusal surface of a tooth. Before each
measurement, calibration was performed for each tooth individually.
The highest reading was recorded for each tooth. Then teeth were
treated with ozone (Prozone, W & H, Austria) for 6 seconds. After
ozonation, teeth were coated with fluorides containing solution. After
that the patient were asked to avoid eating and rinsing of his/her
mouths for 4 hours. Patients were instructed in oral hygiene, which
included mandatory brushing twice a day with a fluoride containing
toothpaste;
• In the fluoride varnish group, like in the ozone group, a
measurement was made with laser infused fluorescence device
(DIAGNOdent, KaVo, Germany). The highest level of each tooth was
21
recorded. Then fluoride varnish (Fluocal solute, Septodont, France)
was applied on molars. After the application, patients were advised to
avoid rinsing their mouths, eating solid foods for 4 hours and cleaning
their teeth until the next day morning. Patients were instructed in oral
hygiene, which included mandatory brushing twice a day with a
fluoride containing toothpaste;
• In the control group, molars were left untreated.
1.6. Questionnaire on oral care and children's dietary habits At baseline of the study, a survey of parents and children was conducted
during dental examination in order to obtain data on children’s oral hygiene and
eating habits. Modified validated questionnaires from WHO international
collaborative study carried out in Latvia (International Collaborative Study,
1993) were used.
1.7. Processing of statistical data of the research The database of the study was created in Microsoft Office Excel
program. Statistical data analysis was performed using IBM SPSS version 20.
In the analysis of data of the study subjects, descriptive and analytical statistical
methods were used. DMF index for teeth and surfaces, as well as for Greene–
Vermillion index, mean and standard deviation values were determined.
Frequency tables were used for description of periodontal health status. Both
indicators were compared between the study groups and within the same group
at different time points (6, 12, 18 and 24 months).
Depending on correlation of data distribution and normal distribution,
the analysis included parametric (t-test, Pearson's x2 or Fisher's exact test) and
22
non-parametric (Wilcoxon or Mann–Whitney test) methods of statistical
analysis. P < 0.05 was considered as the threshold of statistical significance.
The analysis of the survey results included frequency tables, calculation
of percentage distribution of various factors in various groups of the study.
1.8. Ethical considerations of the study The study was approved by the Ethics Committee of Rīga Stradiņš
University. A permission of the Department of Dental therapy and oral health
of Rīga Stradiņš University was received for conducting of the study. All
actions were carried out in accordance with the Declaration of Helsinki
(The World Medical Association Declaration of Helsinki). The study was
conducted in accordance with law of the Republic of Latvia and requirements
for protection of personal data.
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2. RESULTS
2.1. Analysis of oral health status in the study group The first part of the study included 158 ten-year-old children (70 girls,
88 boys) who responded to a call to participate in the study and came to the
first appointment.
2.1.1. Caries intensity At baseline, the mean index was 1.88 (SD=2.01), the mean DME S
– 2.99 (SD=3.59). After 24 months, increased 1.9 times (p<0.001), reaching
3.71 (SD=2.78). The mean also increased (p<0.001), reaching 6.06
(SD=5.45) after 24 months, which is 2 times greater than at baseline. Changes
of caries intensity throughout the study are shown in Figure 2.1.
Figure 2.1. Changes of DMF T and DMF S index throughout the study
1.88 2.34 2.76 3.24 3.71 2.99
3.76 4.8
5.41 6.06
AT BASELINE 6 MON. 12 MON. 18 MON. 24 MON.
Mea
n DM
F in
dex
Time
DMF T DMF S
24
At baseline, the mean number of carious teeth was 0.70 (SD=1.26),
filled teeth – 1.16 (SD=1.5), extracted teeth – 0.03 (SD=0.16). After 24 months,
the highest increase in the number of filled teeth – 2.4 times, reaching 2.73
(SD=2.19) (p<0.001). The number of carious teeth also increased –
up to 0.94 (SD=1.54) and the number of extracted teeth – up to 0.05
(SD=0.22), however this increase was not statistically significant.
Similar changes were also observed in the structure of index. At end of
the study, compared to the baseline, the highest increase in the mean number of
filled surfaces – up to 2.4 times, reaching 4.73 (SD=4.3) of filled surfaces
(p<0.001). Like with, the mean increase of the number of carious and extracted
surfaces was not statistically significant during the study.
At baseline, 129 children still had milk teeth. At baseline, the mean do
in teeth was 3.54 (SD=2.17), while in surfaces – 7.36 (SD=5.35). The mean do
in teeth after 24 months decreased by almost a half (p<0.0005) to 1.93
(SD=1.28).
At baseline, the mean number of teeth affected by initial enamel caries
(Ci) was 1.74 (SD=1.45) (see Figure 3.2.). After 6 months, the number did not
change, but after 12 months, it statistically significantly increased (p=0.02).
After 18 months Ci decreased, however these changes were not statistically
significant. Comparing Ci values at baseline and after 24 months, statistically
significant (p=0.005) increase of 1.42 times, reaching 2.42 (SD=1.95) was
observed.
The mean number of surfaces affected by Ci, at baseline was 2.12
(SD=1.91) (see Figure 2.2.). After 6 months, the number of dental surfaces with
Ci statistically significantly remained unchanged when compared with baseline
values. After 12 months, their number increased statistically significantly
(p=0.0003). Also, after 18 (p=0.013) and 24 months (p<0.0001), the mean
number of surfaces with Ci increased 1.6 times, reaching 3.38 (SD=2.59).
25
Figure 2.2. Changes in number of teeth affected by initial enamel caries
and surfaces throughout the study
At baseline, status of first molars was examined separately, because
these permanent teeth erupt as the first ones. Of all the examined 632 molars,
approximately one third (29.6%) were healthy (see Figure 2.3.). The mean
number of healthy and filled first molars showed no statistically significant
difference (p=0.472). 14.1% of first molars were carious. The number of
Ci affected teeth reached 29.4%.
Figure 2.3. Status of first molars
1.74 1.74
2.29 2.24 2.42 2.12 2.22
3.11 2.92
3.38
0
0.5
1
1.5
2
2.5
3
3.5
4
Atbaseline
6 mon. 12 mon. 18 mon. 24 mon.
Mea
n nu
mbe
r
Time
Teeth
Surfaces
healthy 29,60%
initial caries 29,40%
carious 14,10%
filled 26,0%
extraxted 0,60%
26
2.1.2. Oral hygiene
The mean Greene – Vermillion index was 2.21 (SD=0.99). In all
subsequent time points compared to baseline, the mean Green – Vermillion
index statistically significantly decreased 1.4 times (p<0.05), after 24 months,
this index reaching 1.55 (SD=0.64).
2.1.3. Periodontal status Changes of periodontal status during the study see in Figure 2.4.
At baseline, the mean number of sextants with healthy periodontium was 1.36
(SD=1.99). During the study, it increased, however these changes were not
statistically significant. The mean number of sextants with bleeding gums until
the 12th months increased statistically significantly (p<0.002), however starting
with the 18th month the number decreased. Changes in the number of bleeding
sextants were not statistically significant compared to baseline. The mean
number of sextants with dental calculus was 1.31 (SD=2.11) at baseline. During
the study, the number decreased two times (p<0.001) after 24 months.
Figure 2.4. Changes of periodontal status during the study
1.36 1.62 1.59 1.64
1.84
3.33 3.75 3.92
3.56 3.53
1.31 0.63 0.49
0.8 0.63
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
Atbaseline
6 mon. 12 mon. 18 mon. 24 mon.
Mea
n nu
mbe
r of
sext
ants
Time
Healthy
Bleeding
Calculus
27
2.1.4. Analysis of children dietary and oral care habits When analysing data on frequency of eating, it was found that most
often children eat three or more times a day (44.9% and 54.4%), and only
0.63% eat twice a day. Most children (91%; n=143) tend to eat between meals
on an average 2.3 times a day. Mostly children eat two kinds of products
between meals. Only a small part of the study subjects eats up to 4 different
types of products. Most frequently children eat fruit and sweets (candies,
chocolate, ice cream, etc.); (See Figure 2.5.).
Figure 2.5. Foods that are most widely eaten between meals
Between meals, most children tend to choose two or three kinds of
drinks, the least – four different kinds of drinks. Of drinks, the most children
drink water, tea with sugar and a variety of juice (see Figure 2.6.).
64.6%
46.2%
22.8%
70.3%
9.5%
0%
10%
20%
30%
40%
50%
60%
70%
80%
Sweets Cookies Chips Fruit Other responseProp
ortio
n of
chi
ldre
n (%
)
Types of foods
28
Figure 2.6. Drinks that are most widely chosen used between meals
The analysis of tooth brushing habits showed that 87.4% of children
brush their teeth regularly. More than a half brushes their teeth twice a day.
32.9% brush their teeth once a day (in the morning or in the evening)
(see Figure 2.7). 21% (n=33) of children brush their teeth under parental
supervision.
Figure 2.7. Tooth brushing habits
68% (n=108) of children brush their teeth with a fluoride containing
toothpaste. Only 3% (n=4) of children use fluoride-free toothpaste,
23.4%
51.9%
74.0%
52.5%
10.8% 8.2%
00%10%20%30%40%50%60%70%80%
Sweetsparkling
drinks
Juices Water Tea withsugar
Tea withoutsugar
AnotheranswerPr
opor
tion
of c
hild
ren
(%)
Types of drinks
8.2%
24.7%
52.5%
1.9%
12.6%
00%
10%
20%
30%
40%
50%
60%
Once a day, inthe morning
Once a day, inthe evening
Twice a day More thantwice a day
Occasionally
Prop
ortio
n of
chi
ldre
n (%
)
29
29% (n=46) of parents did not know, whether toothpaste chosen by them for
their children contains fluorides. Fluoride tablets use 16% (n = 25) of children.
Tooth cleaning aids such as dental floss, mouthwash, tongue cleaner,
special toothbrushes use 58% (n=91) of children. Most often, only one type of
aid (85.9%) is used. The most popular aids are mouthwashes and dental flosses
(see Figure 2.8.).
Figure 2.8. The use of oral care aids
60% (n=94) of parents on an average 3–4 times a year change
toothbrushes of their children. 23% (n=37) – do it 1–2 times a year, and 17%
(n=27) – only when the toothbrush has worn out.
80% (n=126) of children make dental appointments on regular basis.
Most children (92%, n=114) do it once or twice a year. A dental hygienist is
regularly visited by only 58% (n=92) of children, 29% (n=46) do it
occasionally, while 13% (n=20) of children have never visited a dental
hygienist. Children who attend dental hygienists on regular basis – 70%
(n=64) do it only once a year.
20.3%
30.4%
13.9%
7.6%
00%
05%
10%
15%
20%
25%
30%
35%
Dental floss Mouthwash Specialtoothbrushes
Tongue cleaner
Chi
ldre
n Pr
opor
tion
(%)
30
2.2. The effectiveness of Ozone on tooth tissue mineralization in caries prevention in premolars
2.2.1. Impact on development of caries The second part of the study included 122 children, analysing in total
457 premolars. Caries development in the study groups was assessed after 6,
12, 18 and 24 months. During 24-months period, caries developed in the
sealants group in 4 teeth, in the varnish group – in 2 teeth, in the ozone group –
in 3 teeth and in the control group – in 14 teeth, in total – in 23 teeth (see Table
2.1.). Caries development incidence in premolars in the study groups showed
no statistically significant difference after 24 months. Most of carious teeth
were observed after 18 months, the least – after 12 and 24 months.
Table 2.1.
Caries development in premolars in the study groups after 6, 12, 18 and 24 months
Time lapse
Ozone group Sealants group Varnish group Control group Number
of carious teeth n (%)
Number of teeth
(n)
Number of carious
teeth n (%)
Number of teeth
(n)
Number of carious
teeth n (%)
Number of teeth
(n)
Number of carious
teeth n (%)
Number of teeth
(n)
6 months 3(2.9) 103 – 78 – 103 4 (2.3) 173 12 months
– 100 – 78 – 103 2 (1.2) 169
18 months
– 100 3 (3.8) 78 2 (1.9) 103 7 (4.5) 156
24 months
– 92 1 (1.3) 75 – 88 1 (0.8) 130
Combining preventive treatment group (ozone, varnishes and sealants)
in one and comparing caries development with the control group, where no
preventive measures were taken, statistically significant changes in the
development of caries were observed (p=0.026).
31
Caries development, depending on tooth surface (occlusal or another –
mesial, distal, lingual, buccal) is showed in Table 2.2.
Table 2.2.
Differences of caries localization in the study groups (n = number of carious teeth)
Tooth surface
Ozone group
n
Varnish group
n
Sealants group
n
Control group
n
Total
Occlusal 3 1 0 9 13 Other 0 1 4 5 10 Total 3 2 4 14 23
Caries development both in occlusal and other surface was
observed equally often. In occlusal surface caries was not observed in sealants
group, but most often it was found in the control group. However, in
another surface, caries was most found in the sealants group and the
control group. The difference in development of caries in occlusal surface of
the study groups was statistically significant (p=0.037), while in other surfaces
these differences were not observed.
2.2.2. Changes of oral health during the study
Analysing oral health status of the study groups, the mean value of and
index increased over the study in all groups. Changes of the mean index over
the study see in Table 2.3. Table 2.3.
Changes of the mean DMF T index over the study
Ozone group Sealants group Varnish group Control group Mean value SD Mean
value SD Mean value SD Mean
value SD
At baseline 2.20 1.79 2.82 3.06 0.95 1.76 2.16 1.85
6 mon. 3.00 2.11 2.33 1.81 1.29 1.90 2.52 1.71 12 mon. 3.37 2.11 3.33 3.22 1.81 2.44 2.92 1.78 18 mon. 3.89 2.18 3.89 3.71 2.33 2.56 3.60 2.35 24 mon. 4.29 2.17 4.63 4.30 3.00 2.88 4.00 2.64
32
At baseline, the mean index between the study groups did not differ
statistically significantly, except for varnish and sealants groups (p=0.023).
After 6 months, difference between the varnish and the ozone groups was
observed (p=0.024). However, after 12, 18 and 24 months, no statistically
significant differences between the study groups were observed in regard to the
mean index.
Changes of the mean index during the study see in Table 2.4.
Table 2.4.
Changes of the mean DMF S index during the study
Ozone group Sealants group
Varnish group Control group
Mean value SD Mean
value SD Mean value SD Mean
value SD
At baseline 4.01 3.81 4.68 5.41 1.36 2.36 3.57 3.56
6 mon. 5.37 4.13 4.11 4.36 2.00 3.08 4.22 3.31 12 mon. 6.32 4.28 6.17 6.60 2.71 3.73 5.20 4.06 18 mon. 7.37 4.49 7.39 7.73 3.38 4.21 5.70 4.72 24 mon. 7.88 4.64 8.38 8.62 4.37 4.63 6.35 5.25
At baseline, the mean index between the study groups did not differ
statistically significantly, except in the varnish and the sealants groups
(p=0.029). After 6 months, it showed statistically significant difference
between the varnish group and the ozone group – in the varnish group, the
mean index was lower than in the ozone group (p=0.024). After 12, 18 and 24
months, no significant differences between the study groups were observed.
The mean number of teeth with initial enamel caries in the study groups
at baseline and after 12, 18, 24 months did not show statistically significant
difference (see Table 2.5.), excluding in the sealants and the ozone group,
where in the sealants group this reading after 6 months was two times lower
than in the ozone group (p=0.038).
33
Table 2.5.
Changes in the number of teeth affected by initial enamel caries during the study
Ozone group Sealants group Varnish group Control group
Mean number of
teeth SD
Mean number of
teeth SD
Mean number of
teeth SD
Mean number of teeth
SD
At baseline 2.35 1.46 1.36 1.00 1.82 1.37 1.69 1.64
6 mon. 2.47 1.54 1.17 1.34 2.09 1.26 1.68 1.48 12 mon. 3.21 1.87 1.61 1.69 2.57 1.80 2.42 2.20 18 mon. 2.79 2.53 1.44 1.89 2.62 1.94 2.36 2.43 24 mon. 3.12 2.09 1.94 1.91 2.74 2.18 2.19 1.83
Changes of the number of Ci affected surfaces during the study see in
Table 2.6. The mean number of surfaces with Ci, in the study groups at baseline
and after 12, 18, 24 months were no statistically significantly different, except
for the sealants and the ozone group, where after 6 months this reading in the
sealants group was 2 times lower than in the ozone group (p=0.014), as well as
differences were also observed between the control and the ozone groups
(p=0.031) – in the control group it was lower than in the ozone group.
Table 2.6.
Changes in the number of initial enamel caries-affected surfaces during the study
Ozone group Sealants group Varnish group Control group Mean
number of
surfaces
SD
Mean number
of surfaces
SD
Mean number
of surfaces
SD
Mean number
of surfaces
SD
At baseline 3.00 1.95 1.73 1.49 2.14 1.83 1.93 1.92
6 mon. 3.42 1.80 1.61 1.69 2.38 1.50 2.06 1.88 12 mon. 4.58 2.63 2.76 2.44 2.90 2.07 3.08 2.55 18 mon. 3.37 2.69 2.06 2.96 3.24 2.51 3.11 3.19 24 mon. 4.24 2.61 3.00 2.94 3.42 2.78 3.26 2.57
34
Analysing the mean value of oral hygiene Greene – Vermillion index,
significant differences between the study groups were observed only after 24
months – between the varnish and the ozone groups (p=0.004) – it was lower in
the varnish group than in the ozone group (1.04 compared to 1.72). Statistically
significant differences were also observed between the control group and the
varnish group (p>0.001) – in the control group, the index was higher than in the
varnish group (1.72 compared to 1.04) (see Table 2.7.).
Table 2.7.
Changes of Greene – Vermillion index during the study
Ozone group Sealants group
Varnish group
Control group
Mean value SD Mean
value SD Mean value SD Mean
value SD
At baseline 1.96 0.99 2.13 0.79 2.28 0.98 2.18 1.02
6 mon. 1.89 0.64 1.87 0.60 1.83 0.54 1.92 0.66 12 mon. 1.99 0.68 1.93 0.64 1.80 0.56 1.89 0.69 18 mon. 1.93 0.61 1.69 0.64 1.60 0.69 1.90 0.74 24 mon. 1.72 0.60 1.39 0.45 1.04 0.48 1.72 0.65
Evaluating the mean number of sextants with a healthy, bleeding
periodontium or dental tartar, no significant differences between the groups
were found during the study.
2.3. The effectiveness of Ozone on tooth tissue mineralization in caries treatment in permanent molars
2.3.1. Impact on the development of caries and DIAGNOdent readings
This part of the study was participated in by 49 children and included
analysis of 88 permanent molars. Regardless to the fact that initial caries
intensity indicators – DMF T and DMF S indices in the varnish group were the
35
lowest, while in the control group – the highest, differences between the groups
were no statistically significant (see Figure 2.9.). Similarly, Greene –
Vermillion index in all groups at baseline did not differ (in the varnish group –
2.3 (SD=1.04), in the ozone group – 1.94 (SD=0.82) and in the control group –
1.66 (SD=0.53)).
Figure 2.9. Caries intensity in different groups at baseline
Determining the depth of caries, at baseline and after 6 and 12 months,
the mean readings of DIAGNOdent in the varnish, the ozone and the control
groups did not differ (see Figure 2.10.). After 18 months the mean
DIAGNOdent reading in the ozone group was 1.4 times lower than in the
control group (p=0.01). This difference remained even after 24 months
(p=0.03). Comparing the varnish and the ozone group, no statistically
significant differences were observed in any time point of the observation.
0.7 1.5
3.5
5.9
1.1 1.9
3.8
7.7
1.5 2
4.7
9.5
0123456789
10
DMFT DMFS df t df s
The
mea
n va
lue
of th
e in
dex
Index
Varnish group
Ozone group
Control group
36
Figure 2.10. The mean DIAGNOdent readings in the study groups over time
During the study, the following impact of treatment on values of caries
depth (DIAGNOdent) was observed in each group of the study:
• In the ozone group, the DIAGNOdent readings after 6 and 12 months
increased, then, after 18, 24 months, it decreased however these
changes were no statistically significant,
• In the varnish group, DIAGNOdent readings increased with every 6
months. In 6, 12, and 18 months, this increase was not significant,
however after 24 months the difference was statistically significant
(p=0.02) compared with baseline readings,
• In the control group, DIAGNOdent reading increased after 6 months
(p=0.006) and 12 months (p<0.0001) and also after 18 and 24 months
DIAGNOdent reading continued to increase (p<0.0001).
2.3.2. Oral health changes during the study
Changes of DMFT and DMFS indices and Greene – Vermillion during
the study are reflected in Figures 2.11. and 2.12., 2.13. Differences of the mean
and index between the study groups during the study were no statistically
significant (see Figures 2.11., 2.12.).
12.56 14.3 14.78 15.11 16.38
12.15 13.7 14.06 14 13.78
12.82 15.04
17.96 20.07 19.68
0
5
10
15
20
25
Atbaseline
6 mon. 12 mon. 18 mon. 24 mon.DIA
GN
Ode
nt m
ean
valu
e
Time
Varnish group
Ozone group
Control group
37
Figure 2.11. Changes of the mean DMF T index in the groups during the study
Figure 2.12. Changes of the mean DMF S index in groups during the study
Also readings of Greene – Vermillion index did not statistically
significantly differ between the groups during the study (see Figure 2.13.)
0.71
1.47 1.88
2.18
2.63
1.06
2
2.53 2.88
3.56
1.47
2.27 2.43 2.79
3.4
0
0.5
1
1.5
2
2.5
3
3.5
4
Atbaseline
6 mon. 12 mon. 18 mon. 24 mon.
Mea
n de
ntal
DM
F in
dex
Time
Varnish groupOzone groupControl group
1.53
2.53
3.24 3.35
4.19
1.88
3.18
4.18
4.81
5.63
2
3
3.43 3.64
4.6
0
1
2
3
4
5
6
Atbaseline
6 mon. 12 mon. 18 mon. 24 mon.
Mea
n D
MF
inde
x in
surf
aces
Time
Varnish groupOzone groupControl group
38
Figure 2.13. Changes of the mean Green – Vermillion index in groups during the study
The mean number of sextants with healthy, bleeding periodontium or
dental tartar and its changes during the study were not statistically significant in
the fluoride varnish, the ozone and the control groups.
2.31
1.92 1.9 1.77
1.34
1.94 1.81 1.73 1.65
1.47 1.66
1.96
1.69 1.7
2.03
0
0.5
1
1.5
2
2.5
Atbaseline
6 mon. 12 mon. 18 mon. 24 mēneši
Mea
n va
lue
of th
e in
dex
Time
VarnishgroupOzonegroupControlgroup
39
3. DISCUSION
3.1. Analysis of oral health status in the study group
Epidemiological studies previously carried out in Latvia show moderate
and high caries prevalence and intensity. Caries intensity in children of this
study can be considered as moderate – reaching 3.71 by 12 years of age. Data
available in the literature show that the mean index in 12–13 years old children
in Latvia in 1998 was 5.75, in Riga – 3.95 (Care and Urtāne, 1999). Five years
later, the mean index in 11-year-old children reached 3.9, and – 6.8, and in
13-year-old children, was 6.1 and – 11.8 (Bērziņa and Care, 2003). According
to the data of Gudkina, in 2010, in 12-year-old children was 4.45 (Gudkina and
Brinkmane, 2010). For comparison – in the world (data collected from 189
countries), in 2011, the mean index in 12-years-old children was 1.67. In
economically highly developed countries, such as Sweden, this index was 0.8,
in Germany – 0.7. In Poland the mean index already was significantly higher –
3.2, in our neighbouring countries Estonia, in 1998, it was – 2.7, while in
Lithuania, in 2005 – 3.7. (http://www.mah.se/CAPP/Country-Oral-Health-
Profiles/EURO/). This suggests that the intensity of caries in our study is very
similar to the one in the neighbouring Lithuania.
Although all patients, regardless of the research group, 2 times a year
were provided with full oral hygiene and patients were motivated to follow
good oral health habits, eat healthy and so on, however, increase of caries
intensity was observed during the study – DMF index both in teeth and surfaces
increased. This leads to a lot of questions – what could be the reason for DMF
index changes, what could be caries contributing factors, and how important is
professional oral care and oral care at home? More detailed analysis of
components of structure of index show that the largest increase in the study
reached the proportion of filled teeth which seems logical, because the children
40
did receive the necessary dental care – including dental filling. Proportion of
carious teeth and surfaces statistically significantly did not change over time,
which indicates a high caries activity. This, in turn, makes us think about
possibly residual caries risk factors in children of our study – frequent snacking
between meals, increased use of carbohydrates-containing products, low quality
or inadequate plaque removal. The children were provided with professional
dental hygiene. Therefore, additional determination of caries risk should be
recommended in the following studies.
In our study, there were accounted teeth with initial enamel caries. At
the age of twelve years, an average of 2.4 teeth were of a potential risk of
progression of initial enamel caries and may require treatment with application
of conservative methods – drilling and filling. Similar results were obtained by
Abanto and co-authors, who observed that those children who are at high risk
of caries, early enamel lesions often tend to progress, rather than to stop. In
children with low caries risk – early enamel lesions tend to regress. (Abanto
et al., 2015).
In our study, a special attention was paid to first molars of permanent
teeth. At baseline, 14% of molars were carious, and even higher percentage
comprised the filled teeth – 26%. As indicated in the literature, children at the
age of 6 to 9 years, have at least 22 to 36% of the first permanent molars that
are carious. (Cho et al., 2001). Goyal et al. emphasizes that the most often
caries affects first permanent molars (80% of all carious teeth) and the most
common locations are in occlusal tooth surfaces (Goyal et al., 2007). As
concluded in some epidemiological study, in first 3 to 4 years after eruption of
teeth, 50% of the first permanent molars become carious (Duruturk et al.,
2011). To avoid these situations, it is necessary to introduce early intervention
strategies.
During the study, a decrease of oral hygiene indicator Greene-
Vermillion index was observed in patients, which is assessable as medium.
41
Changes of periodontal health status were also observed. The mean number of
sextants with healthy periodontium increased, however these changes were not
statistically significant. Dental calculus incidence significantly decreased –
about two times, which could be explained by the fact that patients, on a regular
basis – twice a year – underwent professional dental hygiene, when, if
necessary, their dental calculus was removed. The mean number of sextants
with bleeding gums remained unchanged. In regard to risk factors, plaque index
was determined during appointment to which a child had to be prepared – they
had to brush their teeth, thus eliminating the amount of plaque and, possibly,
influencing final results. Without knowing an appointment time, it would be
possible to address this index at more precise level.
Although the children of the study were provided with a professional
dental hygiene twice a year, oral hygiene habits at home are of tremendous
importance. The children of the study were at the beginning of early puberty
age when parental influence reduces. The older grow children, the more
frequently they have an opportunity to snack outside the home. Lithuanian
colleagues in their study stress out that adolescence is the age when person’s
understanding about teeth cleaning, physical activities, smoking and healthy
diet take down their roots. It is known how difficult is to change bad habits in
adulthood, when they are already deeply rooted in everyday life (Brukiene
et al., 2010). Family is one of the most important social supporters in education
of children (Gift, 1993). In early childhood both parents and other family
members set models for healthy lifestyle. Later, at adolescence, they become a
support group at times when children lack strength and motivation, for
example, to maintain good oral hygiene. (Inglehart and Tedesco, 1995;
Östberg et al., 2002). Also, it should be taken into account that a child depends
on desires and financial capabilities of parents (e.g., in purchases of toothpastes
and toothbrushes) (Gift, 1993).
42
Analysing results of the parental survey, it appears that children often
(on average 2.3 times a day) tend to snack on various sweets, fruit, most often
they drink water, however they also choose tea with sugar and various juices,
thus exposing their teeth to persistent fluctuations of pH. In the study conducted
in Latvia, it was concluded that 6-year-old children daily add to their tea on
average 1.47 teaspoons of sugar (in teaspoon is 5g sugar), while 12-years-old
children add 1.86 teaspoons of sugar, thus daily consuming on average 2.71 and
4.36 tablespoons of sugar (Gudkina and Brinkmane, 2010). Data available in
literature show that caries prevalence in many EU countries have decreased,
despite the fact that consumption of sugar per person per year has remained
roughly the same (≈ 34 kg per person per year) (Touger-Decker, 2003),
frequency of consumption of sugar-containing snacks also does not change
(Reich, 2001). Reduction of caries prevalence is linked mainly to regular use of
fluorides (toothpaste) and improved oral hygiene. If fluorides are taken in
sufficient quantities, diet plays a lesser role in caries prevention (Van Loveren,
2000).
Teenage children would require parental supervision and support.
However, the survey data show that dental cleaning under parental supervision
is carried out only in 21% of 10-year-old children. The survey data show that
32.9% of children cleaned their teeth only once a day. Results of WHO's
international collaborative study conducted in Latvia in 1993 show that 43%
cleaned their teeth once a day (Care and Urtāne, 1999), similar data were stated
also by Polk et al. According to them, 44% of children clean their teeth once a
day or even less often. Tooth cleaning has several advantageous – it provides
both mechanical plaque removal from teeth, as well as a supply of teeth with
fluorides from a toothpaste and water (Polk et al., 2014).
Data obtained during the study show that a fluoride containing
toothpaste was used for teeth cleaning by 68% of children (n=108), 29% of
parents (n=46) did not know whether toothpastes chosen by them for their
43
children contain fluoride. Results of WHO’s international collaborative study
carried out in Latvia in 1993 show that fluoridated toothpaste was used by 45%
of children. Literature data show that fluoridated toothpastes tend to reduce
caries development on average by 24% compared with fluoride-free toothpastes
(Walsh, 2010). Tooth cleaning aids, such as dental floss, mouthwash, tongue
cleaner, and special toothbrushes were used by 58% of children. Of those,
mouthwash and dental floss were used the most widely.
Of concern is the fact that by the age of 10, only 13% of children of the
study group had never visited a hygienist. Guidelines of dentists’ associations
of different countries recommend hygienist’s appointments already from 3
years of age, at least once a year, depending on group of caries risk.
Adolescents are especially advised to undergo professional removal of soft
plaque and dental tartar taking into account each child’s risk of caries and
individual needs (Dean et al., 2011).
Summarizing findings of the study concerning the oral health of 10–12
year old children, it was concluded that caries intensity in permanent teeth was
low at baseline; however, after 24 months caries intensity increased and was
assessed as medium. Oral hygiene and periodontal health of 10-year-old
children was moderate at baseline, but after 24 months, oral hygiene index
Greene – Vermillion decreased and periodontal health status improved.
3.2. The effectiveness of Ozone on tooth tissue mineralization in caries prevention in premolars
Caries prevention is widely addressed in our study. What exactly is
prevention? The term “prevention” in a dictionary is explained as - measures
for prevention of outbreak the spread of infectious diseases, strengthening of
human and environmental health. The term treatment – professional and
individual disease prevention, diagnostic, treatment, rehabilitation and care of
patients, carried out by a medical practitioner (http://www.vm.gov.lv/lv/nozare
44
/terminu_vardnica/). As it is known, as soon as a tooth has erupted, it is
constantly exposed to mild acids leading to changes of mineralisation of
permanent tooth tissues. It is very difficult to draw the line when it comes to
prevention and treatment of caries. Therefore, in regard to dental caries, the
definition “preventive therapy” is increasingly wider used.
Caries development is closely related to a variety of factors, including
microbial reduction. Over time, various methods for disinfection of dental
tissues thus preventing development or progression of caries have been
proposed. Application of ozone in dentistry is a recent novelty (Almaz and
Sönmez, 2013). It is used in almost all dental procedures, because it is devoid
of toxicity and side effects. Ozone is the most powerful oxidant in the world,
causing death of bacterial cells (Bocci et al., 2009) and enabling diffuse of
calcium and phosphate ions in dental tissues, leading to remineralisation of
dental tissues. Ozone destroys micro-organisms in lesions by oxidizing
pyrotartaric acid and CO2, thus increasing pH levels which cause
remineralisation of demineralised tissues by salivary minerals or remineralizing
means (Dähnhardt et al., 2006).
The importance of fluoride in caries prevention is long talked about
(Petersen and Lennon, 2014). Hiiri and co-authors report that fluoride varnishes
statistically significantly reduce caries development both in milk and permanent
bite (Hiiri et al., 2006). Sealants also are regarded as good protectants against
dental caries (Poulsen et al., 2009).
Both fluoride varnish and sealants are effective in prevention of caries.
However, their application is relatively expensive. In regard to the use of ozone
a clinic must take into consideration relatively high costs of an ozone generator
(approximately EUR 5000), as well as needs for regular maintenance thereof.
For an insight, according to price-list of RSU Institute of Dentistry ozonation of
each tooth costs EUR 5, application of sealants are EUR 13 per tooth,
application of fluoride varnishes per tooth – EUR 3. Children up to 18 years of
45
age are entitled for the National Health Service-financed fluoride varnish
application in entire oral cavity. Ozonation and sealants application is not
financed by the NHS.
Duration of a manipulation is a very important factor for adaptation of
any of caries prevention methods. Application of sealants is a relatively time-
consuming process compared to application of a fluoride varnish, which is
often considered to be the most effective in prevention of pit and fissure caries
(Bravo et al., 1997). In contrast, application of ozone takes only a few seconds
and greatly saves a dentist’s time.
In the second part of our study, using various caries prevention methods
(ozone, fluoride varnish and sealants) in the period of 24 months, caries
developed equally in the ozone, the varnish and sealants groups (respectively,
in 3; 2; 4 premolars), while in the control group, caries developed in
14 premolars. However, among the study groups, after 24 months, no
statistically significant differences in effectiveness of prevention methods were
observed. Combining preventive therapy groups (ozone, varnishes and sealants)
in one and comparing caries development in this joint group with the control
group, where no preventive measures were taken, statistically significant
changes in development of caries were observed. This suggests that the use of
one of these caries prevention measures can result in reduction of development
of caries risk. Similarly, Bravo et al in their study found that the use of fluoride
varnish and glass ionomer sealant resulted in finding of no significant
differences between the two caries prevention methods (Bravo et al., 1997).
This same author in another 5-year study concluded that resin based glass
sealant is more effective than fluoride varnish (Bravo et al., 2005).
Caries development both in occlusal and other surfaces was observed
equally often. In occlusal surface caries was not observed in the sealants group,
confirming the effectiveness of sealants in prevention of occlusal surface caries.
Sealants are usually applied on occlusal surfaces of teeth, thus creating a
46
reliable barrier that protects dental fissures and pits from cariogenic bacteria
and environmental impact. Many studies have shown the effectiveness of
sealants in reduction of caries incidence from 87% to 60% (Gordon et al.,
2012).
In our study, ozone was applied occlusally, but regardless to this, caries
developed in occlusal dental surfaces rather than in another. The literature
shows controversial data on antimicrobial effect and efficiency in destruction of
microorganisms in occlusal dental surfaces. There are reliable data on
preventive properties of ozone in therapeutic dentistry prior to etching, filling
and application of sealants (Azarpazhooh and Limeback, 2008). Discussing the
findings of our study, it is noteworthy to know what measures for prevention of
caries were used for children of the study at home. Because it is shown that
maintenance of good oral care habits at home and regular visits to a hygienist,
provide low incidence of caries and periodontal diseases (Axelsson et al.,
2004).
Taking into account the results obtained, in the future it would be
desirable to explore opportunities of combination of preventive methods used
in our study, thereby possibly improving the desired results. Axelsson et al in
their study showed a statistically significant benefit in reducing caries in
children and adolescents through combination of different caries prevention
methods (Axelsson et al., 2004). Johansson confirms that combination of ozone
and fluoride varnish is recommended means for caries prevention (Johansson et
al., 2014).
Analysing oral health status in groups of the second part of the study
groups, the mean DMFT and DMFS indices between the study groups did not
differ statistically significantly at baseline, except in groups of varnishes and
sealants – in the group of sealants, and was higher than in the varnish group.
However, after 24 months, no statistically significant differences in the mean
and index were observed between the study groups. The mean value of DMFT
47
and DMFS indices increased during the study in all groups. As previously
mentioned, this could be caused by several reasons. It should be noted that
caries risk depends on each individual. Individual peculiarities such as low or
high salival pH levels, genetic predisposition, previous caries experience, use of
medications, various immune system-affecting systemic diseases, and personal
oral care habits affects the risk of development of caries (Touger-Decker and
van Loveren, 2003).
The mean number of teeth and surfaces with Ci in the study groups at
baseline and after 24 months showed no statistically significant difference.
Analysing the mean value of oral hygiene Greene – Vermillion index at
baseline, no significant differences between the study groups were found – so it
therefore be assumed that levels of oral hygiene at baseline between the groups
are similar. At the end of the study, namely, after 24 months, the mean
Greene – Vermillion index decreased and oral hygiene improved in all study
groups, excluding the ozone group.
Evaluating the mean number of sextants with healthy, bleeding
periodontium or dental tartar, no significant differences between the groups
were found at baseline and during the study. It could therefore be considered
that periodontal status in all study groups was similar.
Assessing the results, we concluded that ozone, a fluoride varnish and
sealants are equally effective means for caries prevention in premolars.
3.3. The effectiveness of Ozone on tooth tissue mineralization in caries treatment in permanent molars
For the study purposes there were selected occlusal surfaces of teeth, as
they are prone to dental caries due to various reasons. First, the newly erupted
tooth enamel is immature. It contains a relatively high organic component,
which is permeable, thereby exposed to caries attacks. Second, the morphology
of fissures and pits provides favourable environment for retention of plaque and
48
bacterial proliferation. Enamel is thinner in dental fissures and pits, therefore
demineralisation process can be faster. Molars have relatively long eruption
period (1.5–2.5 years), premolars – a few months). This lengthy eruption can
interfere with adequate dental hygiene, because bristles of a toothbrush cannot
easily access occlusal surfaces which are outside distal occlusion and are
difficult to reach (Casamassima et al., 2013). At the age from 7 to 14 years,
when children’s bite changes, eruption of premolars and molars take place.
These dental pits and fissures immediately after eruption are exposed to risk of
caries; however, improving oral hygiene, along with the use of ozone therapy
and special oral care products, it is possible to ensure the greatest protection
against caries.
At baseline, differences of DMFT and DMFS index between the study
groups were no statistically significant. Similarly, oral hygiene
Greene – Vermillion index in all groups did not differ at baseline. Analysing
oral health status in patients of this part of the study, no statistically significant
differences were found in the mean value of DMFT and DMFS index between
the study groups. Also, values of the mean Green – Vermillion index between
the groups did not differ statistically significantly during the study, although in
the control group, the mean value of Greene – Vermillion increased 1.2 times
after 24 months. Changes of CPITN index components between the study
groups were no statistically significant.
During the ozone therapy it is important to observe remineralization
process of demineralized areas. At baseline of our study, the mean value of
DIAGNOdent did not differ between the varnish, the ozone and the control
group. After 6 and 12 months, DIAGNOdent value also did not differ in the
study groups. After 18 months, the mean values of DIAGNOdent was 1.4 times
lower in the ozone group than in the control group (p=0.01). This difference
remained even after 24 months (p=0.03). Comparing the varnish and the ozone
group, no statistically significant differences were observed in any time point of
49
the observation. This suggests that ozone, like fluoride varnish, is an effective
measure in the therapy of initial enamel caries in permanent molars.
As a risk factor that could affect the results of the study should be
considered the fact that the of children of the study, if necessary, were offered
free of charge dental care at the Pediatric Department of the Institute of
Dentistry of RSU, however, a part of the children chose to treat their teeth at
their dentist, closer to their place of residence. Unfortunately, most patients
who underwent dental treatment elsewhere, had filling performed on those
teeth, in which early enamel caries was diagnosed by us, thereby affecting the
final study results. The second risk factor was the exactness of DIAGNOdent
device. As already described in the literature review, the sensitivity of the
device is 0.75 and its specificity is 0.96 (Shi et al., 2001). The DIAGNOdent
device is much more sensitive than other traditional diagnostic methods. It can
often give false positive results in diagnostics of early caries. Bader et al has
mentioned that the use of DIAGNOdent device in clinical trials can cause some
complications. For example, the presence of plaque or pigment can be
interpreted as progression of a carious lesion, and it is very difficult to make
repeated measurements in the same point of dental fissure to be able to compare
results in different time intervals (Bader et al., 2004).
It is very important to detect and treat caries at its early stage. In the
light of the study findings, it can be concluded that ozone not only prevents
dental tissues from the use of invasive methods in removal of carious tissues,
but also initiates stopping of caries and remineralisation of dental tissues.
Ozone therapy is an ideal way to reduce the fear of dental treatment. Often,
dental treatment may be delayed because the patient is very young, fearful and
unwilling to cooperate, which can lead to neglecting of the disease and the need
for radical therapy. It can be widely used in young children.
In our study, similarly to Holmes study, reduction of caries and
remineralisation using ozone was observed (Holmes, 2003). It can be
50
concluded that ozone therapy can be considered an effective means in treatment
of initial enamel caries in permanent molars.
51
4. CONCLUSIONS
1. Intensity of caries in permanent teeth of ten-year-old children was low
(according to WHO) at baseline of the study, namely, = 1.88, however, after
two years it increased and could be considered as moderate (according to
WHO) with = 3.71. Oral hygiene index Greene – Vermillion and
periodontal health at baseline was moderate (according to WHO), after two
years it Greene – Vermillion index decreased to 1.55 (p<0.05), however it
was still considered as moderate (according to WHO). Periodontal health
improved.
2. Ozone, fluoride varnish and sealants are equal means for caries prevention
in premolars, as incidence of caries development in the ozone, the fluoride
varnish and the sealants groups showed no statistically significant
differences after 24 months.
3. Ozone therapy can be considered as effective means for treatment of initial
enamel caries in permanent molars as the mean value of DIAGNOdent, after
24 months was 1.4 times lower in molars of the ozone group than in the
control group (p=0.03).
52
5. PRACTICAL RECOMMENDATIONS
Ozone can be recommended means for caries prevention and treatment
of initial enamel caries. Early treatment of initial caries, rather than long-term
monitoring should be promoted in order to prevent caries progression. For this
purpose, we would recommend the following:
• To organize courses and practical trainings for practitioners on ozone
therapy.
• To introduce the latest caries prevention and treatment methods in
training of dentistry students.
• To introduce the latest caries prevention and treatment methods in
training of hygienists.
We recommend promotion of potentialities of early caries diagnostics
with DIAGNOdent device as follows:
• To arrange courses and practical trainings for medical practitioners on
early caries diagnostics.
• To introduce the latest caries diagnostics methods in training of
dentistry students.
• To introduce the latest caries diagnostics methods in training of
hygienists.
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6. SCIENTIFIC PUBLICATIONS AND REPORTS ON THESTUDY
Articles in internationally peer-reviewed scientific journals 1. Kalniņa J., Care R. Prevention of Occlusal Caries using a Ozone, Sealant and
Fluoride Varnish in Children. Stomatologija. Baltic Dental and Maxillofacial
Journal. 2016; 18(1): 26–31.
Articles in peer-reviewed scientific journals in Latvia 1. Kalniņa J., Care R., Rendeniece I. Ozona terapija kariesa ārstēšanā bērniem.
RSU Zinātniskie raksti, 2012; 2: 151–156.
2. Kalniņa J., Care R., Brinkmane A. Mutes veselības stāvoklis Latvijas 10 gadusveciem bērniem. RSU Zinātniskie raksti 2013; 397–403.
3. Kalniņa J., Care R. Ozona lietošana okluzālā kariesa ārstēšanā: 18 mēnešurezultāti. RSU Zinātniskie raksti 2014; 334–339.
4. Rendeniece I., Brinkmane A., Care R., Kalniņa J. Grūtnieču mutes dobumastāvokļa veselības novērtējums, zināšanas par bērna zobu kopšanas unjaunākām ārstēšanas iespējām. RSU Zinātniskie raksti 2012; 2: 145–150.
Reports in international scientific conferences Presentation at the 4th Scientific conference of Baltic dentists with the poster
report “Ozone therapy for the treatment of dental caries in children”, 9 April2012, Tartu, Estonia
Presentation at FDI 101st Annual World Dental Congress with the posterreport “Oral health status 9–11 years old Latvian children”, 30 August 2013,Istanbul, Turkey.
Presentation at the 12th Congress of European Academy of PaediatricDentistry with the poster report “The influence of ozone, sealants and fluoridevarnish on occlusal caries development in 12 months’ period”, 7 June 2014,Sopot, Poland.
Presentation at the seminar of the 9th European Academy of PaediatricAcademy (EAPD) with the poster report “Ozone treatment of pit and fissurecaries: 24 month results”, 8 May 2015, Brussels, Belgium.
Presentation at the 25th Congress of the International Association of PaediatricDentistry with a poster report “The influence of ozone, sealants and fluoridevarnish on occlusal caries development in 24 months period”, 2 July 2015.Glasgow, United Kingdom.
Presentation in international courses “The cavity-free future – it is possible?”with a lecture “Fluorides and caries”, 26 April 2016, Tartu, Estonia.
54
Reports in scientific conferences in Latvia Presentation at the 6th Baltic preventive dentistry conference with an oral
report “Savlaicīga mutes saslimšanu diagnostika un profilakse”, 11 May 2013,Riga, Latvia.
Presentation in the Conference of Association of Dental Hygienists “Darbaaizsardzība. Ozonterapija” with lecture “Ozona pielietošana zobārstniecībā”,5 April 2014, Riga, Latvia.
Presentation at Riga Stradins University 13th Scientific conference with aposter report “Ozona terapija okluzālā kariesa ārstēšanā: 12 mēnešu rezultāti”,10 April 2014, Riga, Latvia.
Presentation at the 7th Baltic preventive dentistry conference with a posterreport “Izglītošanas un motivācijas ietekme uz mutes dobuma veselību”,17 May 2014, Riga, Latvia.
Presentation atthe conference organized by Dentistry Institute of RSU“Zobārstniecības izglītība, zinātne un prakse neatkarīgajā Latvijā (1994–2014)” with an oral report “Ozonēšana bērnu zobārstniecībā”, 27 June 2014,Riga, Latvia.
Thesis in international scientific conferences
• Kalniņa J., Care R. Ozone therapy for the treatment of dental caries inchildren. Stomatologija, Baltic Dental and Maxillofacial Journal, 2012;14(8): 30.
Kalnina J., Care R., Brinkmane A., Gudkina J. The influence of ozone,sealants and fluoride varnish on occlusal caries development in 12 months’period. 12th Congress of European Academy of Paediatric Dentistry.5–8 June 2014, Sopot, Poland. p. 64.
• Kalnina J., Care R. Ozone treatment of pit and fissure caries: 24 month results.9th European Academy of Paediatric Dentistry seminar and workshop. 8 May2015, Brussels, Belgium. p. 20
• Kalniņa J., Care R. The influence of ozone, sealants and fluoride varnish onocclusal caries development in 24 months period. Int Journal of PaediatricDentistry, 2015; 25(1):92.
Thesis in scientific conferences in Latvia Kalniņa J., Care R., Brinkmane A. Mutes dobuma higiēnas stāvoklis Latvijas
9–11 gadus veciem bērniem. 6th Baltic preventive dentistry conference.11 May 2013, Riga, Latvia.
Kalniņa J., Care R. Ozona terapija okluzālā kariesa ārstēšanā: 12 mēnešurezultāti. Riga Stradins University 13th Scientific conference. 10 April 2014,Riga, Latvia. P. 72.
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